The present invention relates to a system and method for detecting and discriminating between tone signals and voice particularly on a telephone line.
The prior aforementioned application addresses a need to assist and monitor a computer, such as a telephone network special services switch, placing a telephone call over a telephone network. Specifically, that system and method recognizes and distinguishes the various call progress signals and special information signals, for example, which tell the computer that a particular telephone number is not in service.
It has been discovered that certain telephone systems in common use in the United States and abroad handle particular signals on telephone lines differently. Moreover, certain telephone systems inherently remove certain low frequencies that are useful in detecting and discriminating voice from other signals. The present invention relates to an improvement in the basic system and algorithm of the prior application and, in particular, to a modified voice detection scheme as well as other processing speed enhancement aspects.